Role of hip abduction in the kinetics of the thoracic and lumbar spine

The motion of the thoracic and lumbar spine segments was analysed by mean o f the skin landmarks method in 14 volunteers (7 males, 7 females). The resu lts demonstrated that there was no significant difference between men and w omen and there was either facilitation or limitation of the motion of the c haracteristic landmarks of spinal segments during trunk motion in perpendic ular planes. The mobility of spinal segments was associated with pelvic gir dle motion in order to obtain the planned amplitude, and varied with hip jo int abduction. The analysis of the precise mechanisms of relaxing or stretc hing of the pelvivertebral musculo-ligamentous structures constitutes a lar ge field of investigation that necessitates the study of other lower limb p ostures and the use of robotic techniques.